The present invention relates to power transmission belts and methods for manufacturing the power transmission belts.
Belt transmission systems for driving accessories of automobiles include a serpentine drive system in which, for example, a V-ribbed belt is wrapped around a crank shaft pulley, a power steering pulley, an air conditioning pulley, a water pump pulley, and an AC generator pulley, for example. Some of the belt transmission systems of this type are configured to give tension to a V-ribbed belt by pushing the back surface of the V-ribbed belt using an auto tensioner or a flat pulley such as a fixed idler pulley.
Japanese Unexamined Patent Publication No. 2005-61593 discloses providing a rubber layer having an uneven pattern of woven cloth without layering a cover canvas on the back surface of the V-ribbed belt, to reduce noise made, for example, by adhesion abrasion due to contact of the back surface of the V-ribbed belt with the idler pulley.